A camera may be used to acquire information about a place or an object. The information is visual image data generated by the camera corresponding to the scene falling within the field of view of the camera.
A sensing device may be used to acquire other information about a place or an object. Such information may be conditions sensed by the sensing device, such as one or more environmental conditions surrounding the sensing device.
An access control device is a specific type of sensing device that senses whether an identifying token has been presented to the access control device and whether that token is authenticated.
In some situations, the camera and/or the sensing device may be connected to a data network so that image data and/or sensing data may be received by other devices connected to the network.